1. Field
This document relates to a flexible rechargeable battery.
2. Description of the Related Art
With the development of mobile technology, the demand for rechargeable batteries as a source of energy is increasing. Rechargeable batteries are batteries that are designed to be charged and discharged repeatedly, unlike primary batteries.
One of the important factors in the manufacture of rechargeable batteries is energy density. Rechargeable batteries used in small electronics are inserted into an electronic device and used as a power supply.
In small electronics, the volume or capacity and form factor of the power supply are set because the size of the electronic device is restricted and determined in advance in terms of design. With the trend toward information devices having a smaller size, power supply sizes are also getting smaller in size.
In addition, consumers are demanding higher capacity as rechargeable batteries now have longer use time and have become smaller in size. That is, volumetric energy density needs to be increased. Accordingly, there is a demand for rechargeable batteries which have less unnecessary space and are compact.
For example, a pouch-type rechargeable battery includes an electrode assembly that is formed by laminating positive electrodes, separators, and negative electrodes to perform charging and discharging, a pouch that accommodates the electrode assembly, and electrode tabs that enable the electrode assembly to be pulled out of the pouch.
In the pouch-type rechargeable battery, the empty space between the electrode assembly and the pouch is made as small as possible, just large enough to allow an electrolyte solution into that space, and the overall volume of the battery is reduced or minimized by applying vacuum to the inside.
When the rechargeable battery is flexible, however, the electrode assembly slips inside the pouch; therefore, space is needed inside the pouch for flexible bending, even if it means the battery's energy density will be decreased.
Moreover, the vacuum process, to be conducted after injection of the electrolyte solution into the pouch, will reduce or minimize the overall volume of the rechargeable battery while decreasing the internal pressure. The pouch-type rechargeable battery that underwent the vacuum process will cause the positive electrodes, separators, and negative electrodes to slip less.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form prior art.